<target name="jdepend" description="Generate dependency metrics for each package">
    <jdepend format="xml" outputfile="${jdepend.dir}/jdepend-report.xml">
        <classpath>
            <pathelement path="classes" />
        </classpath>
    </jdepend>
</target>

BUILD FAILED
build.xml:59: Missing classespath required argument
    at org.apache.tools.ant.taskdefs.optional.jdepend.JDependTask.execute(JDependTask.java:397)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
    at org.apache.tools.ant.Task.perform(Task.java:364)
    at org.apache.tools.ant.Target.execute(Target.java:341)
    at org.apache.tools.ant.Target.performTasks(Target.java:369)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1216)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1185)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:40)
    at org.eclipse.ant.internal.ui.antsupport.EclipseDefaultExecutor.executeTargets(EclipseDefaultExecutor.java:32)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1068)
    at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:423)
    at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137)

if (getSourcespath() == null && getClassespath() == null) {
    throw new BuildException("Missing classespath required argument");
} else if (getClassespath() == null) {
    String msg = "sourcespath is deprecated in JDepend >= 2.5 - please convert to classespath";
    log(msg);
}

public Path getClassespath() {
    return classesPath;
}

public void setClasspath(Path classpath) {
    if (compileClasspath == null) {
        compileClasspath = classpath;
    } else {
        compileClasspath.append(classpath);
    }
}